Richard Horton ridiculed over primitive surgical research methods in a famous commentary in the Lancet more than two decades ago [9]. Surgical research was compared with a comic opera-where questions are shouted out, but without answers. Horton stated BI should like to shame [surgeons] out of the comic opera performances which they suppose are statistics of operations.^The dominating study method in neurosurgery, namely retrospective series of surgeons evaluating their own work is often hopelessly biased and the scientific value may certainly be questioned. Without well-conducted randomized controlled trials (RCTs), can we really advance and know what works and what does not? And before we discuss the optimal surgical management, do we really know that surgery helps at all? Surgery has traditionally been more experience based than evidence based, and much of the enormous advancements in of surgical treatment over the last 200 years have taken place without rigorous scientific trials [6]. Still, there are several thought-provoking examples of surgical interventions that have failed the test of a sham-controlled randomized trial, for example arthroscopic knee surgery for degenerative osteoarthrosis or meniscal tears [15,20], subacromial decompression for shoulder impingement [17], diaphragm pacing in ALS [7], deep brain stimulation in the ventral capsule/ventral striatum for depression [5], renal denervation for hypertension [1], and vertebroplasty for osteoporotic vertebral fractures [2]. In fact, an overwhelming majority of sham-controlled trials in surgery fail to demonstrate an effect of the intervention [18]. Does this mean that surgery often is less effective than we like to believe? Or does it merely reflect the fact that few surgical interventions can be placebo controlled and that such trials are more often done when the likelihood of surgery being an effective treatment is low in the first place? Nevertheless, very few surgical treatments have been placed under the scrutiny of such trials and many operations are still backed by relative scarce and often conflicting evidence, not at least in neurosurgery.Martin and colleagues [14] conducted an interesting and well-written systematic review with critical appraisal of RCTs that compare neurosurgical interventions with nonoperative therapy. They identified 82 neurosurgical RCTs published between 2000 and 2017. More than a third of the trials found a difference between operative and non-operative treatment, but in less than 4% non-operative management was found to be superior. However, most trials were conducted by surgeons, and this can be a source of bias as the genealogy of scientist may have an impact on their findings [8]. Further, high JADAD score, reflecting better methodological quality [10], was associated with lower chance of demonstrating a benefit from surgery. The JADAD scale places much emphasis on blinding and the inter-rater agreement for the JADAD scale has been questioned [3]. Still, almost half of the neurosurgical studies in the current rev...